Physics 1.A 400N box is being pushed across a level floor at a constant speed by a force P of 100N at an angle of 30⁰ to the horizontal. What is the coefficient of kinetic friction between the box and the floor? A. 0.19 B. 0.35 C. 0.12 D. 0.25 2.A 5 kg box rests on a horizontal surface with a coefficient of static friction of 0.4. What is the minimum horizontal force required to just start moving the box? A. 10 N B. 15 N C. 20 N D. 25 N 3.A 10 kg body is placed on an inclined plane of 30°. If the coefficient of friction is 0.2, what is the net force acting down the plane? (Take g = 10 m/s²) A. 30 N B. 40 N C. 50 N D. 60 N 4.Which of the following does not affect the frictional force between two surfaces? A. Normal force B. Nature of surfaces C. Area of contact D. Coefficient of friction 5.Which of these pairs can balance a 10 N force? A. 8 N and 6 N at 90° B. 5 N and 5 N at 60° C. 7 N and 7 N at 120° D. 3 N and 3 N at 180° Chemistry 6.A gas sample with an initial volume of 3.25dm-³ is the heated and allowed to expand to 9.75dm-³ at constant pressure. What is the ratio of the final absolute temperature to the initial absolute temperature A. 3:1 B. 5:2 C. 5:4 D. 8:3 7.Which of the following statements is correct A. At constant, temperature, the volume increases as the pressure decreases B. At constant pressure, the volume increases as the temperature increases C. The average kinetic energy of a gas is directly proportional to its temperature D. All of the above 8.Which of the following statements is NOT correct regarding Le Chatelier’s Principle? A. Increasing pressure favors fewer gas molecules B. Increasing temperature favors endothermic reactions C. Catalysts shift equilibrium positions D. Removing a product shifts equilibrium to the right 9.What mass of calcium carbonate is required to produce 44 g of CO₂? A. 40 g B. 50 g C. 100 g D. 110 g (Ca=40, C=12, O=16) 10.For the endothermic reaction: C(s) + CO₂(g) ⇌ 2CO(g) What happens when temperature increases? A. Yield of CO decreases B. Yield of CO increases C. Reaction shifts left D. No effect

Here are the solutions to your physics and chemistry questions: Physics 1. A 400N box is being pushed across a level floor at a constant speed by a force P of 100N at an angle of 30⁰ to the horizontal. What is the coefficient of kinetic friction between the box and the floor? Step 1: Resolve the applied force P into horizontal and vertical components. The applied force P = 100 N at an angle of 30^ below the horizontal (since it's "pushed at an angle"). Horizontal component: $P_x = P (30^) = 100 N × (